Dillard U.S. Pat. No. 5,588,942 discloses an adjustable exercise device. First and second rigid bars may be connected together by a support to form an elongated bar assembly having a longitudinal axis. A pair of hand grips are spaced from one another, and each hand grip includes a mounting portion which is freely pivotally supported on a bar for pivotal movement about pivot axis extending substantially perpendicular to the longitudinal axis of the bar assembly. A hand grip portion is supported on the mounting portion for swivel movement through 360 degrees about an axis of rotation disposed substantially perpendicular to and passing through the pivot axis at the point where the mounting portion is pivotally supported by the bar assembly. The swivel connection can be locked to prevent swiveling of the hand grip portion.
Mobley U.S. Pat. No. 7,066,866 discloses a chin-up bar assembly with sliding and swiveling handles. A chin up bar assembly is provided with a cross bar and a pair of handles slidably mounted on the cross bar. The handles are pivotally mounted for movement between locked and unlocked positions. When a user hangs from the handles, the handles automatically pivot to the locked position to frictionally engage the cross bar and prevent sliding movement of the handles along the cross bar. The handles also can be swiveled during use to exercise different muscles in the user's arms, chest and back.
Hauser et al U.S. Pat. No. 7,540,831 discloses a pull-up exercise assembly with rotatable handles and pivotable bar. An exercise assembly for performing a wide array of exercises including pull-ups and chin-ups is provided which includes a bar connected between rotatable swing arm assemblies. The swing arm assemblies extend along vertical faces of a frame and are adapted to rotate the bar from one position between the vertical faces to another position. The exercise assembly includes at least one handle assembly removably grasping the central bar and having a handle adapted to rotate 360 degrees during exercise.